A CONTINUOUSLY VARIABLE TRANSMISSION DEVICE WITH GEAR REGULATION DEVICE

Description

[0001] The present invention relates to a transmission system, in particular a continuously variable transmission system for motorcycles, provided with a regulation device of the gear shift curve, according to the preamble of claim 1 and as it is disclosed in JPS61171947A.

[0002] In this document the term "motorcycle" means a vehicle with two, three or four wheels, pivoting or non-pivoting, such as the Vespa®, Ape® or MP3® vehicles marketed by the Applicant.

[0003] The Continuously Variable. Transmission (CVT) is a type of automatic transmission for vehicles in which the transmission ratio can vary continuously between two limit values. The continuous transmission is widely used in two-wheeled vehicles with a small and medium engine size, in particular motor scooters.

[0004] In a CVT, the variation of the transmission ratio takes place by varying the winding diameter of the belt on two pulleys, one of which is the drive pulley and the other driven, and at least one of these has the ability to draw together and distance the two parts or half-pulleys which it is composed of.

[0005] Typically, the drive pulley comprises a speed regulator made with centrifugal masses, generically referred to as "rollers", which have the task of realizing the axial drawing together of the respective half-pulleys, passing from the low gear condition (half-pulleys distant) to the condition of high gear (half-pulleys juxtaposed).

[0006] Devices are known of for regulating the gear shift curve, which, when the CVT is in the low gear condition, allow blocking of some of the rollers, thus preventing them from participating in the juxtaposition of the half-pulleys. Said half-pulleys thus reach a predefined axial distance at a greater number of engine revolutions, giving the CVT a more sporting set-up.

[0007] Conversely, if all the rollers participate in the juxtaposition of the half-pulleys, these find themselves at said axial distance at a lower number of engine revolutions, giving the CVT a more touring set-up.

[0008] An example of embodiment of such a device for the adjustment of the gear shift curve is described in the document WO-A1-2013/098689 in the name of the Applicant.

[0009] However, such a regulation device has the drawback of allowing activation and deactivation only in the presence of the low gear condition, i.e. when the rollers are next to the drive shaft, to avoid impact due to the sudden release of the rollers in the gear shift phase.

[0010] The object of the present invention is to provide a transmission device which satisfies the needs mentioned above and which at the same time overcomes the drawbacks of the prior art.

[0011] Such purpose is achieved by a transmission device made according to claim 1. The dependent claims describe embodiment variants.

[0012] The characteristics and advantages of the transmission device will be evident from the description given below, by way of a non-limiting example, according to the appended drawings, wherein:

• figure 1 shows a transmission device for vehicles according to a preferred embodiment of the present invention;
• figure 2 shows a longitudinal cross-section view of the transmission device in figure 1, in a low gear configuration and with the regulation device off;
• figure 3 shows the transmission device in figure 2, in a high gear configuration, with the regulation device off;
• figure 4 shows a longitudinal cross-section view of the transmission device in figure 1, in a low gear configuration and with the regulation device on;
• figure 5 shows the transmission device in figure 4, in a high gear configuration, with the regulation device on;
• figures 6a and 6b show a roller of the transmission device according to the present invention;
• figure 7 shows a graph of the gear shift trend in a transmission device according to the present invention.

[0013] With reference to the appended drawings, reference numeral 1 globally denotes a continuously variable transmission device, configured to be applied preferably to a two / three-wheel motorcycle, engaged with a drive shaft 2 which defines an axis of rotation X.

[0014] The transmission device 1 comprises a first drive pulley 4, driven in rotation by the drive shaft 2, and a second driven pulley (not shown), connected to each other by a V-belt 6.

[0015] The drive pulley 4 is composed of a first half-pulley 8 and a second half-pulley 10, respectively provided with facing, truncated-cone active surfaces 8a, 10a, sliding along said axis of rotation X so as to juxtapose and distance the active surfaces 8a, 10a, and integral with each other in rotation.

[0016] The first half-pulley 8 comprises a speed regulator 12 comprising a container 14, integral in translation with the active surface 8a, provided with a contoured seat 16, and a plurality of special rollers 18, housed in the seat 16.

[0017] The special rollers 18 are provided with engagement means suitable to be pushed by counter-engagement means of the transmission device.

[0018] The rollers realize centrifugal masses which, as the number of engine revolutions increases, push the first half-pulley 8 towards the second half-pulley 10. This way, the winding diameter of the belt 6 on the drive pulley 4 increases and the belt, not being able to stretch, operates to decrease the winding diameter on the driven pulley, increasing the transmission ratio (high gear).

[0019] To such purpose the seat 16 is provided with a bottom surface 16a which the rollers, having a tapered shape towards the second half pulley 10 slide on, so that, when the rollers move centrifugally, they push the container 14 towards the second half pulley 10.

[0020] Each roller 18 comprises a movable body 19, intended to move, preferably to drag, on the bottom surface 16a of the seat 16 and the cover 20, and a stem 21 that extends away from the mobile body 19, ending with a foot 24.

[0021] The stem 21 forms an example of said engagement means suitable to be pushed by counter-engagement means of the transmission device.

[0022] The drive pulley 4 further comprises, preferably, a roller contrast cover 20, for example fixed to the drive shaft 2, suitable to contain the rollers 18 in the seat 16.

[0023] The transmission device 1 further comprises a gear shift regulation device able to influence the movement of the rollers 18 as a function of an axial load adjustable independently of the number of revolutions of the motor shaft.

[0024] In particular, the gear shift regulation device is able to influence the movement of the rollers 18 so as to accentuate the centrifugal movement as a function of an axial load adjustable independently of the number of revolutions of the motor shaft.

[0025] The gear shift regulation device comprises an abutment element 22, for example in the shape of a flange coaxial to the motor shaft 2 having a predefined radial extension, placed facing the seat 16 of the container 14, in such a way that the rollers 18 are axially arranged between said abutment element 22 and the bottom surface 16a of the seat 16. The abutment element 22 is suitable to influence the rollers 18 to facilitate the axial displacement thereof and thus realize an example of said counter-engagement means.

[0026] The regulation device comprises axial action means suitable to exert on the element abutment 22 an axial action of adjustable intensity.

[0027] In particular, said axial action means comprise a transmission slide 26, for example supported by the motor shaft 2, movable axially to drag the abutment element 22 and bring it axially to push the rollers 18 on the bottom surface 16a of the seat 16, thus facilitating the centrifugal displacement thereof by virtue of the configuration of said bottom surface 16a.

[0028] Furthermore, the axial action means comprise an actuating pin 28 movable axially and axially constrained to the transmission slide 26, the actuating pin 28 has an axial extension such that a head 30 of said pin 28 protrudes from the drive pulley 4, on the side of the second semi-pulley 10, i.e. on the side opposite that of the drive shaft 2.

[0029] The axial action means further comprises an elastic element 32, for example fitted on the actuating pin 28 to influence it permanently in the direction in which the abutment element 22 juxtaposes the bottom surface 16a.

[0030] For example, the elastic element 32 is in compression between the head 30 of the pin 28 and an axially fixed abutment 34, preferably external to the pulley 4.

[0031] The axial action means further comprise an inhibiting device suitable to operate to regulate the intensity of the axial action exerted by said axial action means on the abutment element 22.

[0032] For example, said inhibiting device operates on the pin 28 in the direction to counteract the action of the elastic element 32, for example by pushing said pin 28 in the direction moving the abutment element 22 away from the bottom surface 16a.

[0033] Consequently, when the inhibiting device is switched off, there is an axial load of the spring that is transmitted to the rollers and is added to the centrifugal action to move the rollers centrifugally.

[0034] Preferably, the inhibiting device comprises a support element 36 that operates axially on the pin 28, a threaded bushing 38 that operates on the support element 36, and a housing 40 provided with a threaded portion 42, on which the threaded bushing 38 is screwed.

[0035] The inhibiting device also comprises a toothed wheel 44 provided with a splined shaft 46 coupled for rotation with the threaded bushing 38, and a worm gear 48 that meshes with the toothed wheel 44, realising a skewed-axis kinematic mechanism.

[0036] The inhibiting device lastly comprises an electric motor 50 coupled with the worm gear 48 to rotatably actuate it.

[0037] In a first configuration, the low gear is engaged and the gear shift regulation device is off (figure 2).

[0038] The rollers are arranged in a radial internal limit position.

[0039] In this configuration, the axial action means are configured so as not to transmit to the abutment element 22 any axial load drawing the abutment element 22 towards the bottom surface 16a.

[0040] To such purpose, the threaded bushing 38 is screwed onto the threaded portion 42 of the housing 40, so as to counteract the action of the elastic element 32 on the pin 28.

[0041] Consequently, upon an increase of the engine revolutions, the rollers 18 undergo a centrifugal movement, without the abutment element 22 influencing said displacement.

[0042] The transition into a high gear is thus achieved with the regulation device off (Figure 3).

[0043] In this configuration, the limit position of the rollers 18, defined outer radial limit position, is defined by the cover 20, which keeps them in the seat 16.

[0044] If, starting from this configuration, the regulation device is progressively activated, the axial action means operate on the abutment element 22 with an action approaching the bottom surface 16a, until said abutment element 22 engages the rollers 18 (in particular, the foot 24 of the stem 22), without changing its position.

[0045] In order for the axial action means to operate on the abutment element 22, the threaded bushing 38 is unscrewed from the threaded portion 42 of the housing 40, so as to limit the counter action to the elastic element 32.

[0046] In a further configuration, the low gear is engaged and the gear shift regulation device is switched on (figure 4). The rollers 18 are arranged in a radial internal limit position.

[0047] In such a configuration, the axial action means transmit to the abutment element 22 an axial load moving the abutment element 22 towards the bottom surface 16a, so as to push the rollers on the bottom surface 16a and increase the centrifugal movement.

[0048] To such purpose, the threaded bushing 38 is unscrewed from the threaded portion 42 of the housing 40, so as not to counteract the action.of the elastic element 32 on the pin 28.

[0049] As a result, as the engine revolutions increase, the rollers 18 will have the tendency to move centrifugally, to a greater extent than in the condition with the axial action means switched off.

[0050] The transition into a high gear is however achieved with the regulation device on (Figure 5).

[0051] In this configuration, the abutment element 22 preferably remains in contact with the foot 24 of the rollers 18; if the regulation device is switched off, the abutment element 22 instead detaches from the roller 18. The configuration assumed by the transmission device is the one which the device would assume at the current engine revolutions with the regulation device switched off.

[0052] Figure 7 shows a graph with the number of revolutions of the drive pulley given as a function of the number of revolutions of the driven pulley, in condition of the regulation device off (curve D), so that the vehicle set-up is more sporting, in condition of the regulation device on (curve I), so that the vehicle set-up is more touring and in an intermediate condition (M) in which the regulation device, initially off, is switched on during the gear shift.

[0053] Innovatively, the transmission system according to the present invention overcomes the drawbacks mentioned with reference to the prior art since it permits changing of the gear shift curve both at low and at high speeds.

[0054] Advantageously, moreover, by switching on the regulation device in a low gear condition, it shifts the gear change to towards lower revolutions, lowering the clutch coupling in the start-up phase.

Claims

1. Continuously variable transmission device (1) for a two-, three- or four-wheel motorcycle, connectable to a drive shaft (2), comprising:

- a drive pulley (4) rotatable about a rotation axis (X), comprising a first half-pulley (8) carrying a first active surface (8a) and a second half-pulley (10) carrying a second active surface (10a), a V-belt (6) being arranged between said active surfaces (8a,10a);

- a speed regulator (12) comprising a container (14), provided with a seat (16) having a bottom surface (16a), and special rollers (18) provided with engagement means, movable by centrifugal action on said bottom surface (16a), moving radially and axially with respect to this and thus imposing an axial sliding to said first half-pulley (8);

- a gear shift regulation device suitable to operate on said rollers (18) through an axial action adjustable independently of the number of engine revolutions, to influence the centrifugal movement of the rollers (18) and so influence the gear shift, wherein said gear shift regulation device comprises
an abutment element (22) facing the seat (16) of the container (14), in such a way that the rollers (18) are axially arranged between said abutment element (22) and the bottom surface (16a) of the seat (16), and
axial action means suitable to exert on the element abutment (22) an axial action of adjustable intensity;
characterised in that in a first configuration wherein the gear shift regulation device is off, the axial action means are configured so as not to transmit to the abutment element (22) any axial load drawing the abutment element (22) towards the bottom surface (16a), and in a further configuration wherein the gear shift regulation device is switched on, the axial action means transmit to the abutment element (22) an axial load moving the abutment element (22) towards the bottom surface (16a).

2. Transmission device according to claim 1, wherein the gear shift regulation device of the changed is able to influence the movement of the rollers (18) so as to accentuate the centrifugal movement as a function of an axial load adjustable independently of the number of revolutions of the drive shaft.

3. Transmission device according to claim 1 or 2, characterised in that in the first configuration wherein the gear shift regulation device is off, the abutment element (22) detaches from the roller (18).

4. Transmission device according to any of the previous claims, characterised in that in the further configuration wherein the gear shift regulation device is switched on, the abutment element (22) remains in contact with a foot (24) of the rollers (18).

5. Transmission device according to any of the previous claims, wherein said axial action means comprise an actuation pin (28), operatively bound axially to the abutment element (22), and an elastic element (32) configured to permanently influence the actuation pin (28) to permanently influence it in the direction of approach of the abutment element (22) to the bottom surface (16a).

6. Transmission device according to any of the previous claims, wherein the axial action means comprise an inhibiting device suitable to operate to regulate the intensity of the axial action exerted by said axial action means on the abutment element (22).

7. Transmission device according to claim 5 and 6, wherein said inhibiting device operates on the pin (28) in the sense of opposing the action of the elastic element (32).

8. Transmission device according to claim 7, wherein the inhibiting device comprises a support element (36) that operates axially on the pin (28), a threaded bushing (38) that operates on the support element (36), and a housing (40) provided with a threaded portion (42), on which is screwed the threaded bushing (38).

9. Transmission device according to claim 8, wherein the inhibiting device also comprises a toothed wheel (44) provided with a splined shaft (46) coupled for rotation with the threaded bushing (38), and a worm gear (48) that meshes with the toothed wheel (44), realising a skewed-axis kinematic mechanism.

10. Transmission device according to claim 9, wherein the inhibiting device comprises an electric motor (50) coupled with the worm gear (48) to rotatably actuate it.

11. Special roller (18) for a gear shift regulation device of a transmission device (1) according to any of claims 1 to 10, comprising a mobile body (19) and engagement means suitable to be pushed by counter-engagement means of the regulation device to accentuate the centrifugal movement.

12. Special roller according to claim 10, wherein said engagement means comprise a stem (21) that extends away from the mobile body (19).

Ansprüche

1. Stufenlos verstellbare Getriebevorrichtung (1) für ein zwei-, drei-oder vierrädriges Motorrad, die mit einer Antriebswelle (2) verbunden werden kann, umfassend:

- eine Antriebsscheibe (4), die um eine Drehachse (X) drehbar ist, mit einer ersten Halbscheibe (8), die eine erste aktive Fläche (8a) trägt, und einer zweiten Halbscheibe (10), die eine zweite aktive Fläche (10a) trägt, wobei zwischen den aktiven Flächen (8a, 10a) ein Keilriemen (6) angeordnet ist;

- einen Geschwindigkeitsregler (12), umfassend einen Behälter (14), der mit einem Sitz (16) mit einer Bodenfläche (16a) versehen ist, und Spezialrollen (18), die mit Eingriffsmitteln versehen sind, die durch Zentrifugalwirkung auf die Bodenfläche (16a) beweglich sind, sich radial und axial in Bezug auf diese bewegen und somit der ersten Halbscheibe (8) eine axiale Gleitbewegung auferlegen;

- eine Gangschalt-Regelvorrichtung, die geeignet ist, durch eine axiale Wirkung, die unabhängig von der Motordrehzahl einstellbar ist, auf die Rollen (18) einzuwirken, um die Zentrifugalbewegung der Rollen (18) zu beeinflussen und so die Gangschaltung zu beeinflussen, wobei die Gangschalt-Regelvorrichtung umfasst
ein Anschlagelement (22), das dem Sitz (16) des Behälters (14) zugewandt ist, derart, dass die Rollen (18) axial zwischen dem Anschlagelement (22) und der Bodenfläche (16a) des Sitzes (16) angeordnet sind, und
axial wirkende Mittel, die geeignet sind, auf das Anschlagelement (22) eine axiale Wirkung von einstellbarer Intensität auszuüben;
dadurch gekennzeichnet, dass in einer ersten Konfiguration, in der die Gangschalt-Regelvorrichtung ausgeschaltet ist, die Axialwirkungsmittel so konfiguriert sind, dass sie auf das Anschlagelement (22) keine Axiallast übertragen, die das Anschlagelement (22) in Richtung der Bodenfläche (16a) zieht, und in einer weiteren Konfiguration, in der die Gangschalt-Regelvorrichtung eingeschaltet ist, die Axialwirkungsmittel auf das Anschlagelement (22) eine Axiallast übertragen, die das Anschlagelement (22) in Richtung der Bodenfläche (16a) bewegt.

2. Getriebevorrichtung nach Anspruch 1, wobei die Gangschalt-Regeleinrichtung des Wechselgetriebes in der Lage ist, die Bewegung der Rollen (18) so zu beeinflussen, dass die Fliehkraftbewegung in Abhängigkeit von einer unabhängig von der Drehzahl der Antriebswelle einstellbaren Axiallast akzentuiert wird.

3. Getriebevorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass sich in der ersten Konfiguration, in der die Gangschalt-Regelvorrichtung ausgeschaltet ist, das Anschlagelement (22) von der Rolle (18) löst.

4. Getriebevorrichtung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, dass in der weiteren Konfiguration, in der die Gangschalt-Regelvorrichtung eingeschaltet ist, das Anschlagelement (22) mit einem Fuß (24) der Rollen (18) in Kontakt bleibt.

5. Getriebevorrichtung nach einem der vorstehenden Ansprüche, wobei die axial wirkenden Mittel einen Betätigungsstift (28), der axial mit dem Anschlagelement (22) wirkverbunden ist, und ein elastisches Element (32) umfassen, das so konfiguriert ist, dass es den Betätigungsstift (28) permanent beeinflusst, um ihn permanent in der Richtung der Annäherung des Anschlagelements (22) an die Bodenfläche (16a) zu beeinflussen.

6. Getriebevorrichtung nach einem der vorhergehenden Ansprüche, wobei die axial wirkenden Mittel eine Hemmvorrichtung umfassen, die dazu geeignet ist, die Intensität der axialen Wirkung zu regulieren, die von den axial wirkenden Mittel auf das Anschlagelement (22) ausgeübt wird.

7. Getriebevorrichtung nach den Ansprüchen 5 und 6, wobei die Hemmvorrichtung auf den Stift (28) in dem Sinne wirkt, dass sie der Wirkung des elastischen Elements (32) entgegenwirkt.

8. Getriebevorrichtung nach Anspruch 7, wobei die Hemmvorrichtung ein Stützelement (36), das axial auf den Stift (28) wirkt, eine Gewindebuchse (38), die auf das Stützelement (36) wirkt, und ein Gehäuse (40) umfasst, das mit einem Gewindeabschnitt (42) versehen ist, auf den die Gewindebuchse (38) aufgeschraubt ist.

9. Getriebevorrichtung nach Anspruch 8, wobei die Hemmvorrichtung auch ein Zahnrad (44) umfasst, das mit einer Keilwelle (46) versehen ist, die zur Drehung mit der Gewindebuchse (38) gekoppelt ist, und ein Schneckenrad (48), das mit dem Zahnrad (44) kämmt, wodurch ein kinematischer Mechanismus mit schräger Achse realisiert wird.

10. Getriebevorrichtung nach Anspruch 9, wobei die Hemmvorrichtung einen Elektromotor (50) umfasst, der mit dem Schneckenrad (48) gekoppelt ist, um dieses drehend zu betätigen.

11. Spezialrolle (18) für eine Gangschalt-Regelvorrichtung einer Getriebevorrichtung (1) nach einem der Ansprüche 1 bis 10, umfassend einen beweglichen Körper (19) und Eingriffsmittel, die geeignet sind, durch Gegeneingriffsmittel der Regelvorrichtung geschoben zu werden, um die Zentrifugalbewegung zu akzentuieren.

12. Spezialrolle nach Anspruch 10, wobei die Eingriffsmittel einen Schaft (21) umfassen, der sich von dem beweglichen Körper (19) weg erstreckt.

Revendications

1. Dispositif de transmission à variation continue (1) pour une motocyclette à deux, trois ou quatre roues, apte à être connecté à un arbre d'entraînement (2), comprenant :

- une poulie d'entraînement (4) apte à tourner autour d'un axe de rotation (X), comprenant une première demi-poulie (8) portant une première surface active (8a) et une seconde demi-poulie (10) portant une seconde surface active (10a), une courroie trapézoïdale (6) étant agencée entre lesdites surfaces actives (8a, 10a) ;

- un régulateur de vitesse (12) comprenant un contenant (14), muni d'un siège (16) ayant une surface inférieure (16a), et des rouleaux spéciaux (18) munis de moyens de mise en prise, mobiles par action centrifuge sur ladite surface inférieure (16a), se déplaçant de manière radiale et axiale par rapport à celle-ci et imposant ainsi un coulissement axial à ladite première demi-poulie (8) ;

- un dispositif de régulation de passage de vitesse approprié pour agir sur lesdits rouleaux (18) au travers d'une action axiale réglable, indépendamment du nombre de tours du moteur, pour influencer le mouvement centrifuge des rouleaux (18) et ainsi influencer le passage de vitesse, dans lequel ledit dispositif de régulation de passage de vitesse comprend
un élément de butée (22) faisant face au siège (16) du contenant (14), d'une manière telle que les rouleaux (18) sont agencés axialement entre ledit élément de butée (22) et la surface inférieure (16a) du siège (16), et
des moyens d'action axiale appropriés pour exercer sur la butée de l'élément (22) une action axiale d'intensité réglable ;
caractérisé en ce que dans une première configuration dans laquelle le dispositif de régulation de passage de vitesse est désactivé, les moyens d'action axiale sont configurés de façon à ne pas transmettre à l'élément de butée (22) de charge axiale tirant l'élément de butée (22) en direction de la surface inférieure (16a), et dans une autre configuration dans laquelle le dispositif de régulation de passage de vitesse est activé, les moyens d'action axiale transmettent à l'élément de butée (22) une charge axiale déplaçant l'élément de butée (22) en direction de la surface inférieure (16a).

2. Dispositif de transmission selon la revendication 1, dans lequel le dispositif de régulation de passage de vitesse du changé est apte à influencer le mouvement des rouleaux (18) de façon à accentuer le mouvement centrifuge en fonction d'une charge axiale réglable indépendamment du nombre de tours de l'arbre d'entraînement.

3. Dispositif de transmission selon la revendication 1 ou 2, caractérisé en ce que dans la première configuration dans laquelle le dispositif de régulation de passage de vitesse est désactivé, l'élément de butée (22) se détache du rouleau (18).

4. Dispositif de transmission selon l'une quelconque des revendications précédentes, caractérisé en ce que dans l'autre configuration dans laquelle le dispositif de régulation de passage de vitesse est activé, l'élément de butée (22) reste en contact avec un pied (24) des rouleaux (18).

5. Dispositif de transmission selon l'une quelconque des revendications précédentes, dans lequel lesdits moyens d'action axiale comprennent une broche d'actionnement (28), liée de manière fonctionnelle et de manière axiale à l'élément de butée (22), et un élément élastique (32) configuré pour influencer de façon permanente la broche d'actionnement (28) pour l'influencer de façon permanente dans la direction d'approche de l'élément de butée (22) vers la surface inférieure (16a).

6. Dispositif de transmission selon l'une quelconque des revendications précédentes, dans lequel les moyens d'action axiale comprennent un dispositif d'inhibition approprié pour fonctionner pour réguler l'intensité de l'action axiale exercée par lesdits moyens d'action axiale sur l'élément de butée (22).

7. Dispositif de transmission selon la revendication 5 et 6, dans lequel ledit dispositif d'inhibition agit sur la broche (28) dans le sens d'opposition à l'action de l'élément élastique (32).

8. Dispositif de transmission selon la revendication 7, dans lequel le dispositif d'inhibition comprend un élément de support (36) qui agit de manière axiale sur la broche (28), une douille filetée (38) qui agit sur l'élément de support (36) et un boîtier (40) muni d'une partie filetée (42), sur laquelle est vissée la douille filetée (38).

9. Dispositif de transmission selon la revendication 8, dans lequel le dispositif d'inhibition comprend également une roue dentée (44) munie d'un arbre cannelé (46) couplé pour une rotation avec la douille filetée (38), et un engrenage à vis sans fin (48) qui s'engrène avec la roue dentée (44), réalisant un mécanisme cinématique à axe oblique.

10. Dispositif de transmission selon la revendication 9, dans lequel le dispositif d'inhibition comprend un moteur électrique (50) couplé avec l'engrenage à vis sans fin (48) pour l'actionner en rotation.

11. Rouleau spécial (18) pour un dispositif de régulation de passage de vitesse d'un dispositif de transmission (1) selon l'une quelconque des revendications 1 à 10, comprenant un corps mobile (19) et des moyens de mise en prise appropriés pour être poussés par des moyens de mise en prise opposée du dispositif de régulation pour accentuer le mouvement centrifuge.

12. Rouleau spécial selon la revendication 10, dans lequel lesdits moyens de mise en prise comprennent une tige (21) qui s'étend en s'éloignant du corps mobile (19).

Drawing